APEX

Agricultural Policy/Environmental eXtender

CONTACTS

Jimmy Williams	Hydraulic Engineer	TAES	(254) 774-6124
Avery Meinardus	Computer Assistant	TAES	(254) 774-6110

MODEL OBJECTIVE

To provide a tool for managing whole farms or small watersheds to obtain maximum production efficiency and maintain environmental quality.

MODEL COMPONENTS

• Subarea--Epic
  • Hydrology
  • Weather
  • Erosion(water and wind)
  • N and P cycling
  • Pesticide fate
  • Soil temperature,
  • Plant growth
  • Tillage
  • Plant environmental control
  • Economics.
• Routing
  • Overland flow
  • Channels
  • Flood plains
  • Water
  • Sediment
  • Nutrients
  • Pesticides

MODEL OPERATION

• Farm or watershed may be divided into several (<100)subareas or fields
• Daily time step - long term simulations (1-4000 yrs)
• Soil, weather, tillage and crop parameter data supplied with model
• Soil profile can be divided into thirty layers
• Homogeneous subareas
• Weather generation is optional
  

  MANAGEMENT CAPABILITIES

  Whole farm - - routing allows evaluation of interactions between fields (surface run-on, sediment deposition and degradation, nutrient and pesticide transport, and subsurface flow).
  
  Examples: terrace systems, grass waterways, strip cropping, buffer strips, crop rotations, fertilizer, irrigation, liming, furrow diking, drainage, waste management (feed yards, dairies with or without lagoons)